Vitamin D levels and status amongst asthmatic and non-asthmatic adolescents in Cyprus: a comparative cross-sectional study

Table 4 Difference in Vitamin D levels by asthma severity indicators in active asthmatics

Asthma severity indicators		Vitamin D	Difference in mean Vitamin D levels between negative and positive response
		Mean levels
		Ng/mL (SD)	(Reference Group: Negative) ^§
		n = 69±	b coefficient (95% CI); p value
		n = 69±	Model 1*	Model 2*
Asthma attacks in the last 12 months
No	59.4%	21.58 (5.54)	−3.10	−3.05
Yes	40.6%	19.41 (5.40)	(−5.80, −0.41); p = 0.03	(−6.07, −0.04); p = 0.05
Asthma medication use
No	62.3%	21.38 (5.31)	−2.00	−1.80
Yes	37.7%	19.35 (5.78)	(−4.92, 0.92); p = 0.18	(−4.82, 1.22); p = 0.24
Hospital admission
No	82.2%	21.07 (5.28)	−2.90	−2.40
Yes	18.8%	18.52 (6.45)	(−6.18, 0.67); p = 0.11	(−6.13, 1.34); p = 0.20
Emergency room visit
No	65.2%	21.77 (5.04)	−3.43	−3.76
Yes	34.8%	18.72 (5.89)	(−6.18, −0.67); p = 0.02	(−6.74, −0.79); p = 0.01
Asthma severity index
No Positive Answers	29.5%	22.62 (4.84)	−1.51^†	−1.55^†
1 Positive Answer	26.2%	21.13 (5.57)	(−2.64, −0.37); p = 0.01	(−2.78, −0.33); p = 0.01
2 Positive Answers	23.0%	19.75 (5.28)
3 Positive Answers	16.4%	18.50 (6.18)
4 Positive Answers	4.9%	16.43 (6.58)

Notes: ^§b coefficients correspond to difference in mean vitamin D levels as estimated in linear regression models. *Model 1adjusted for seasonality. Model 2 further adjusting for gender, family history of Allergies, body fat %, smoking status and parental education. ±Missing data ranged from 0–8. ^†Change in mean vitamin D levels per 1 unit change in asthma severity index (i.e. across increasing categories of severity).

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